Flame spreaders



J. T. ALGER FLAME SPREADERS June 6, 1961 5 Sheets-Sheet 1 Filed Oct. 28,1957 FIG. 1

INVENTOR. 'Jrry 77191967 BY WM i/z YM I n7 dgiarneqs June 6, 1961 3Sheets-Sheet 2 Filed Oct. 28, 1957 .P s 9 2 m M w W .a E w d. J v M M wV w M M @Q a United States Patent 2,987,119 FLAME SPREADERS Jerry T.Alger, Chicago, Ill., assignor, by mesnc assignments, to Configured TubeProducts (30., St. Louis, Mo., a corporation of Missouri Filed Oct. 28,1957, Ser. No. 692,824 3 Claims. (Cl. 158-113) This invention relates toflame deflectors or spreaders for use on burners adapted to consumegaseous fuel.

One object of the present invention is to provide a new and improvedflame spreader that will produce an extremely wide, flat, downwardlyinclined flame, of a type well adapted for use in water heaters andother gas appliances.

A further object is to provide a new and improved flame spreader whichis so arranged that the flame will not readily flash back or blow out.

Further objects and advantages of the present invention will appear fromthe following description, taken with the accompanying drawings, inwhich:

FIG. 1 is a small-scale side elevational view of a water heater burnerequipped with a flame spreader that will be described as an illustrativeembodiment of the present invention.

FIG. 2 is a bottom view of the burner and flame spreader, takengenerally as indicated by the line 2-2 in FIG. 1.

FIG. 3 is an elevational sectional view, taken generally along the line3-3 in Fig. 2.

FIGS. 4 and 5 are top and bottom plan views of the flame spreader.

FIG. 6 is a side elevational view of the flame spreader.

FIG. 7 is an end view, showing the inner end of the flame spreader.

FIG. 8 is a plan view of a modified flame spreader.

FIG. 9 is a side elevatioual view of the flame spreader of Fig. 8.

FIG. 10 is a front elevational view showing the flame spreader of FIG.8.

FIG. 11 is a fragmentary enlarged sectional view, taken generally alonga line 1111 in Fig. 8.

FIG. 12 is a transverse sectional view, taken along a line 1212 in FIG.11.

FIG. 13 is a plan view showing a flame spreader which is somewhatmodified with respect to the flame spreader of Figs. 8-12.

FIG. 14 is a side elevational view showing the flame spreader of FIG.12.

As already indicated, FIG. 1 shows an application of the invention to awater heater 10, having a burner 12 equipped with a flame spreader 14.The burner 12 may be of a known type having a mixture tube 16 whichdischarges a mixture of gas and air in a horizontal direction. In theillustrated application, the mixture tube 16 is bent into the form of anelbow, for the sake of compactness. Thus, the mixture tube 16 has anentrance portion 18 which is vertical, and an exit or discharge portion20 which is horizontal. An axially directed discharge port 22 is formedin the end of the discharge portion 20. It will be seen that the mixturetube 16 is turned inwardly around the discharge port 22 so as to form aninturned annular flange 24.

In this case, the water heater 10 is in the form of a tank having acylindrical sidewall 26. A bottom wall 28 is mounted across the lowerportion of the sidewall 26 but is spaced upwardly from the lower end ofthe sidewall so as to form a chamber 30 for the burner 12. A stack orflue pipe 32 extends upwardly through the water heater 10 andcommunicates with the burner chamber 30. It will be seen that the burner12 is positioned at one side of the burner chamber 31) and is iceadapted to provide a flame 31 which extends to the other side of thechamber and then sweeps upwardly along the bottom wall 28. The flamedoubles back along the bottom wall toward the burner and then passesupwardly into the flue pipe 32. It will be seen that the flue pipe 32 isoff center and is on the same side of the water heater as the burner 12.

In order to produce this flame pattern, the flame spreader 14 isprovided with lower and upper bowls 34 and 36. It will be seen that thelower bowl 34- is upright in position on concave upwardly. It will beseen that the illustrated bowl 34 is spherically curved and is somewhatless than hemispherical in extent. However, the shape of the lower bowl34 may be varied considerably in order to change the pattern of theflame 31. One edge portion of the bowl 34 is formed into a generallysemi-cylindrical mounting stub 38 which fits around the lower portion ofthe mixture tube 16 at its outer end, as clearly shown in FIGS. 3 and 5.The mounting portion 38 may be welded, clamped or otherwise secured tothe mixture tube 16. Horizontal flanges 40 extend laterally from theupper edges of the semi-cylindrical mounting stub 38.

From FIG. 3 it will be apparent that the edge portion of the lower bowl34 opposite from the mounting stub 38 extends upwardly into the path ofthe combustible mixture discharged from the mixture tube 16. The uppermargin of the lower bowl 34 is approximately at the level of the axis ofthe burner tube 16. It will be seen that the upper margin of the bowl 34is rounded upwardly into a horizontal flange or lip 42. The effect ofthe lower bowl 34 is to deflect the combustible mixture upwardly intothe upper bowl 36.

As illustrated, the upper bowl 36 is considerably larger in diameter andsomewhat flatter than the lower bowl 34. It will be seen that the upperbowl 36 is inverted in position or is concave downwardly. In theillustrated arrangement, the upper bowl is spherically curved but isquite flat and constitutes much less than a hemisphere.

As in the case of the lower bowl 34, the upper bowl 36 has one edgeportion formed into a generally semi-cylindrical mounting stub 44 whichfits over the upper portion of the mixture tube 16 at its outer end.Horizontal flanges 46 may be formed at the lower edges of the mountingstub 44 and may be arranged to abut against the corresponding flanges411 on the lower bowl 34. The flanges 4t) and 46 may be welded orotherwise secured together.

The lower margin of the upper bowl 36 extends downwardly into the pathof the mixture discharged from the mixture tube 16. The level of thelower margin on the upper bowl 36 is approximately the same as that ofthe upper margin on the lower bowl 34. An outwardly extending horizontalflange 48 is provided around the lower margin of the upward bowl 36. Dueto its greater extent, the upper bowl 36 extends outwardly from theburner tube 16 a considerably greater distance than the lower bowl 3 4.

Thus, the combustible mixture deflected upwardly by the lower bowl 34 isdeflected downwardly and spread laterally by the upper bowl 36. Theresult is the wide, flat, downwardly inclined flame 31 shown in FIGS. 1and 2. The flame pattern may be changed by varying the shape of thebowls 34 and 36. Thus, the size and curvature of the bowls may bechanged to vary the size and shape of the flame. Moreover, the bowls maybe made oblong rather than circular, and otherwise may be varied inshape.

It will be seen that the marginal portions of the lower and upper bowls34 and 36 are generally aligned with each other adjacent to the mountingstubs 38 and 44. The burner tube 16 is received between the mountingstubs so as to project part way into the bowls from the margins thereof.The opposite margin of the upper bowl extends considerably beyond theopposite margin of the lower bowl.

In addition to deflecting the main part of the fuelai-r mixture upwardlyinto the upper bowl, the lower bowl directs a small part of the mixturelaterally to form small lateral retaining flames which stabilize themain flame. Thus, the action of the flame spreader is to protect themain flame from flashing back or blowing out.

The flame spreader is well adapted for use in applications where thereis a natural draft, as shown in FIG. 1, or where a forced draft isutilized to blow the outer end of the flame through a heat exchanger orthe like.

FIGS. 842 illustrate a modified flame spreader 60 which also has upperand lower flame-shaping bowls 62 and 64. However, the bowls 62 and 64are of somewhat different shape than the bowls employed in the flamespreader of FIGS. 1-7. As before, the upper bowl 62 is concavedownwardly, and the lower bowl 64 is concave upwardly, but the shape ofeach bowl is similar to that of a shallow rounded shovel or scoop.

The upper bowl 62 has a main or upper wall portion 63 which is concavedownwardly and of a shallow, approximately frusto-conical curvature.From FIG. 9, it will be seen that the concave wall portion 63 has alower margin 65 which is substantially in a horizontal plane. In thiscase, the margin 63 has a rounded front portion 66 (FIG. 8) and a pairof angularly related side portions '67. Along the margin 65, the curvedwall 63 is formed into a substantially flat horizontal flange 68.

Similarly, the lower bowl 65 has a main or lower wall portion 69 whichis concave upwardly and of a shallow, approximately frusto-conicalcurvature. The curved wall 64 is provided with an upper margin 70 whichis substantially in a horizontal plane. From FIG. 8, it will be seenthat the margin 70 has a rounded front portion 71 and a pair ofangularly related side portions 72. Along the margin 70, the lower bowl64 is formed with a flange 73 which is turned downwardly at an acuteangle. The lower margin 65 of the upper bowl 62 and the upper margin 70of the lower bowl 64 are in substantially thesame horizontal plane, butthe upper bowl extends outwardly to a substantial extent beyond thelower bowl, to define a slot or opening '74 through which the flameescapes.

As shown to best advantage in FIGS. 9 and 11, the flow of secondary airalong the outer surfaces of the upper and lower bowls 62. and 64 iscontrolled by upper and lower flanges or baflles 75 and 77 which aremounted thereon. The flanges 75 and 77 extend along the margins 65 and70 and are spaced back from the marginal flanges 68 and 73. It will beseen that the upper flange 75 is turned upwardly, while the lower flange77 is turned downwardly. The flanges 75 and '77 may be welded orotherwise secured to the upper and lower bowls 62 and 64.

The flanges 75 and 77 deflect the secondary air upwardly and downwardlyfrom the margins 65 and 70 of the upper and lower bowls. In this way,the flanges 75 and 77 prevent any streams of high velocity secondary airfrom striking the base of the flame adjacent the margins 65 and 7G. Wereit not for the flanges or baflles 75 and 77, such high velocity airstreams might tend to lift or tear the flame away from the margins ofthe bowls 62 and 64, in which case the burner would operate in asomewhat unstable, noisy manner.

The rear end portions of the upper and lower bowls 62 and 64 are formedinto opposite semicylindrical mounting stubs '76 and 73 with opposedhorizontal wings or flanges 80 and 82 extending outwardly therefrom. Theupper and lower flanges or wings 80 and 82 may be welded or otherwisesecured togethe In the illustrated construction, welds are indicated at84. The opposed semicylindrical stubs 76 and 78 are adapted to bemounted around the front end of a burner tube 86. The extreme rear endsof the wings 80 on the upper bowl 62 4 are formed into mounting brackets88 whereby the flame spreader and the burner tube may be mounted on asuitable support (not shown).

The curved upper and lower walls 63 and are connected to the wings and82 by steeply sloping, generally triangular walls 90 and 92 which closethe rear end of the cavity between the bowls and prevent rearward escapeof the combustible mixture. Thus, the combustible mixture fans outwardlyto form a short broad flame 94, as indicated by the flame patterns shownin FIGS. 8 and 9. After being directed upwardly into the upper bowl 62by the lower bowl 64, the combustible mixture is directed downwardly bythe upper bowl, so that the merging flame is downwardly directed at asmall angle. Of course, the heat of the flame causes the flame to beswept upwardly as it fans outwardly.

In the construction of FIGS. 8-12, the short, wide character of theflame is made more pronounced by providing a deflecting member 98 withinthe cavity between the bowls 62 and 64. As illustrated, the deflectingmember d8 has a pair of generally vertical flanges 100 which aresymmetrically disposed on opposite sides of the burner axis and arearranged to diverge from each other in a forward direction. The flanges100 are joined at one end by a web 102 which may be welded or otherwisesecured to one of the bowls, preferably the upper bowl 62, as shown. Inthis case, each of the vertical flanges 10% has a lower edge 104 whichis spaced upwardly a short distance from the lower bowl 64. Thediverging flanges 100 have the effect of spreading the combustiblemixture outwardly so as to broaden and shorten the flame. This will beapparent from a comparison of FIG. 8 with FIG. 13, which shows amodifled flame spreader in which the deflecting member 98 is omitted.Otherwise, the flame spreader 110 is the same as the flame spreader 60of FIGS. 8-l2. It will he observed that the flame spreader 110 producesa flame 112 which is somewhat longer and narrower than the flame 94produced by the flame spreader 60. Either the flame spreader 60 or theflame spreader 110 may be employed in various situations depending uponthe desired shape of the flame.

The flame spreaders of FIGS. 8-14 may be employed very advantageously inwater heaters, driers and other appliances for which a broad, flat,short flame is desired. It has been found that the spreaders produce ahighly stable flame which will resist blowing out and flashing back evenin a forced draft of air.

I claim:

1. A flame spreader comprising: an inverted shallow upper bowl; anupright shallow lower bowl of lesser horizontal extent than said upperbowl, said lower bowl having upper rearward edge portions thereofengaging lower rearward edge portions on said upper bowl along asubstantially horizontal plane, each of said bowls having curved edgeportions extending along said plane forwardly from said engaging edgeportions to form an unobstructed continuous curved rim for each bowl,each of said rims lying along said plane throughout substantially itsentire extent, the rim on said lower bowl being spaced inwardly from therim on said upper bowl so as to provide a downwardly dischargingcrescent-shaped outlet from the hollow body formed by said opposedengaging bowls; an integral inverted trough-shaped stub communicatingwith the interior of said upper bowl and extending rearwardly fromrearward portions of said upper bowl; an integral upright trough-shapedstub communicating with the interior of said lower bowl and extendingrearwardly from rearward portions of said lower bowl, and having edgeportions engaging with edge portions on said inverted stub along saidplane so as to form a tubular mounting means whereby said flame spreaderis adapted for mounting on a complementary burner tube having an axialdischarge port; and means for joining the two stub portions together.

2. The combination of claim 1 including an outwardly inclined baffleflange mounted on forward exterior portions of at least one of saidbowls, said flange being disposed slightly inwardly of, substantiallycoextensive with, and parallel to the unobstructed rim of the bowl uponwhich said flange is mounted, said flange adapted to divert secondaryair away from the last-mentioned rim.

3. A flame spreader comprising: an inverted shallow upper bowl; anupright shallow lower bowl of lesser horizontal extent than said upperbowl, said lower bowl having upper rearward edge portions thereofengaging lower rearward edge portions on said upper bowl along asubstantially horizontal plane, each of said bowls having curved edgeportions extending along said plane forwardly from said engaging edgeportions to form an unobstructed continuous curved rim for each bowl,each of said rims lying along said plane throughout substantially itsentire extent, the rim on said lower bowl being spaced inwardly from therim on said upper bowl so as to provide a downwardly dischargingcrescent-shaped outlet 20 from the hollow body formed by said opposedengaging bowls; means on said upper bowl forming a semicircular openingin said rearward edge portion thereof and communicating with theinterior of said upper bowl; and means on said lower bowl forming asemicircular opening in said rearward edge porton thereof andcommunieating with the interior of said lower bowl; said semicircularopenings being opposite each other to form a circular openingcommunicating with the interior of said hollow body and adapted toreceive a complementary burner tube having an axial discharge port.

References Cited in the file of this patent UNITED STATES PATENTS1,285,665 Franklin Nov. 29, 1918 1,518,223 Schott et al. Dec. 9, 19241,707,451 Thomas et a1. Apr. 2, 1929 2,588,759 Poschadel Mar. 11, 19522,766,819 Little Oct. 16, 1956 2,867,272 Morrison Jan. 6, 1959

